RESTinio
gzwrite.c
Go to the documentation of this file.
1 /* gzwrite.c -- zlib functions for writing gzip files
2  * Copyright (C) 2004-2017 Mark Adler
3  * For conditions of distribution and use, see copyright notice in zlib.h
4  */
5 
6 #include "gzguts.h"
7 
8 /* Local functions */
9 local int gz_init OF((gz_statep));
10 local int gz_comp OF((gz_statep, int));
11 local int gz_zero OF((gz_statep, z_off64_t));
12 local z_size_t gz_write OF((gz_statep, voidpc, z_size_t));
13 
14 /* Initialize state for writing a gzip file. Mark initialization by setting
15  state->size to non-zero. Return -1 on a memory allocation failure, or 0 on
16  success. */
18  gz_statep state;
19 {
20  int ret;
21  z_streamp strm = &(state->strm);
22 
23  /* allocate input buffer (double size for gzprintf) */
24  state->in = (unsigned char *)malloc(state->want << 1);
25  if (state->in == NULL) {
26  gz_error(state, Z_MEM_ERROR, "out of memory");
27  return -1;
28  }
29 
30  /* only need output buffer and deflate state if compressing */
31  if (!state->direct) {
32  /* allocate output buffer */
33  state->out = (unsigned char *)malloc(state->want);
34  if (state->out == NULL) {
35  free(state->in);
36  gz_error(state, Z_MEM_ERROR, "out of memory");
37  return -1;
38  }
39 
40  /* allocate deflate memory, set up for gzip compression */
41  strm->zalloc = Z_NULL;
42  strm->zfree = Z_NULL;
43  strm->opaque = Z_NULL;
44  ret = deflateInit2(strm, state->level, Z_DEFLATED,
45  MAX_WBITS + 16, DEF_MEM_LEVEL, state->strategy);
46  if (ret != Z_OK) {
47  free(state->out);
48  free(state->in);
49  gz_error(state, Z_MEM_ERROR, "out of memory");
50  return -1;
51  }
52  strm->next_in = NULL;
53  }
54 
55  /* mark state as initialized */
56  state->size = state->want;
57 
58  /* initialize write buffer if compressing */
59  if (!state->direct) {
60  strm->avail_out = state->size;
61  strm->next_out = state->out;
62  state->x.next = strm->next_out;
63  }
64  return 0;
65 }
66 
67 /* Compress whatever is at avail_in and next_in and write to the output file.
68  Return -1 if there is an error writing to the output file or if gz_init()
69  fails to allocate memory, otherwise 0. flush is assumed to be a valid
70  deflate() flush value. If flush is Z_FINISH, then the deflate() state is
71  reset to start a new gzip stream. If gz->direct is true, then simply write
72  to the output file without compressing, and ignore flush. */
73 local int gz_comp(state, flush)
74  gz_statep state;
75  int flush;
76 {
77  int ret, writ;
78  unsigned have, put, max = ((unsigned)-1 >> 2) + 1;
79  z_streamp strm = &(state->strm);
80 
81  /* allocate memory if this is the first time through */
82  if (state->size == 0 && gz_init(state) == -1)
83  return -1;
84 
85  /* write directly if requested */
86  if (state->direct) {
87  while (strm->avail_in) {
88  put = strm->avail_in > max ? max : strm->avail_in;
89  writ = write(state->fd, strm->next_in, put);
90  if (writ < 0) {
91  gz_error(state, Z_ERRNO, zstrerror());
92  return -1;
93  }
94  strm->avail_in -= (unsigned)writ;
95  strm->next_in += writ;
96  }
97  return 0;
98  }
99 
100  /* run deflate() on provided input until it produces no more output */
101  ret = Z_OK;
102  do {
103  /* write out current buffer contents if full, or if flushing, but if
104  doing Z_FINISH then don't write until we get to Z_STREAM_END */
105  if (strm->avail_out == 0 || (flush != Z_NO_FLUSH &&
106  (flush != Z_FINISH || ret == Z_STREAM_END))) {
107  while (strm->next_out > state->x.next) {
108  put = strm->next_out - state->x.next > (int)max ? max :
109  (unsigned)(strm->next_out - state->x.next);
110  writ = write(state->fd, state->x.next, put);
111  if (writ < 0) {
112  gz_error(state, Z_ERRNO, zstrerror());
113  return -1;
114  }
115  state->x.next += writ;
116  }
117  if (strm->avail_out == 0) {
118  strm->avail_out = state->size;
119  strm->next_out = state->out;
120  state->x.next = state->out;
121  }
122  }
123 
124  /* compress */
125  have = strm->avail_out;
126  ret = deflate(strm, flush);
127  if (ret == Z_STREAM_ERROR) {
128  gz_error(state, Z_STREAM_ERROR,
129  "internal error: deflate stream corrupt");
130  return -1;
131  }
132  have -= strm->avail_out;
133  } while (have);
134 
135  /* if that completed a deflate stream, allow another to start */
136  if (flush == Z_FINISH)
137  deflateReset(strm);
138 
139  /* all done, no errors */
140  return 0;
141 }
142 
143 /* Compress len zeros to output. Return -1 on a write error or memory
144  allocation failure by gz_comp(), or 0 on success. */
145 local int gz_zero(state, len)
146  gz_statep state;
147  z_off64_t len;
148 {
149  int first;
150  unsigned n;
151  z_streamp strm = &(state->strm);
152 
153  /* consume whatever's left in the input buffer */
154  if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
155  return -1;
156 
157  /* compress len zeros (len guaranteed > 0) */
158  first = 1;
159  while (len) {
160  n = GT_OFF(state->size) || (z_off64_t)state->size > len ?
161  (unsigned)len : state->size;
162  if (first) {
163  memset(state->in, 0, n);
164  first = 0;
165  }
166  strm->avail_in = n;
167  strm->next_in = state->in;
168  state->x.pos += n;
169  if (gz_comp(state, Z_NO_FLUSH) == -1)
170  return -1;
171  len -= n;
172  }
173  return 0;
174 }
175 
176 /* Write len bytes from buf to file. Return the number of bytes written. If
177  the returned value is less than len, then there was an error. */
178 local z_size_t gz_write(state, buf, len)
179  gz_statep state;
180  voidpc buf;
181  z_size_t len;
182 {
183  z_size_t put = len;
184 
185  /* if len is zero, avoid unnecessary operations */
186  if (len == 0)
187  return 0;
188 
189  /* allocate memory if this is the first time through */
190  if (state->size == 0 && gz_init(state) == -1)
191  return 0;
192 
193  /* check for seek request */
194  if (state->seek) {
195  state->seek = 0;
196  if (gz_zero(state, state->skip) == -1)
197  return 0;
198  }
199 
200  /* for small len, copy to input buffer, otherwise compress directly */
201  if (len < state->size) {
202  /* copy to input buffer, compress when full */
203  do {
204  unsigned have, copy;
205 
206  if (state->strm.avail_in == 0)
207  state->strm.next_in = state->in;
208  have = (unsigned)((state->strm.next_in + state->strm.avail_in) -
209  state->in);
210  copy = state->size - have;
211  if (copy > len)
212  copy = len;
213  memcpy(state->in + have, buf, copy);
214  state->strm.avail_in += copy;
215  state->x.pos += copy;
216  buf = (const char *)buf + copy;
217  len -= copy;
218  if (len && gz_comp(state, Z_NO_FLUSH) == -1)
219  return 0;
220  } while (len);
221  }
222  else {
223  /* consume whatever's left in the input buffer */
224  if (state->strm.avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
225  return 0;
226 
227  /* directly compress user buffer to file */
228  state->strm.next_in = (z_const Bytef *)buf;
229  do {
230  unsigned n = (unsigned)-1;
231  if (n > len)
232  n = len;
233  state->strm.avail_in = n;
234  state->x.pos += n;
235  if (gz_comp(state, Z_NO_FLUSH) == -1)
236  return 0;
237  len -= n;
238  } while (len);
239  }
240 
241  /* input was all buffered or compressed */
242  return put;
243 }
244 
245 /* -- see zlib.h -- */
246 int ZEXPORT gzwrite(file, buf, len)
247  gzFile file;
248  voidpc buf;
249  unsigned len;
250 {
251  gz_statep state;
252 
253  /* get internal structure */
254  if (file == NULL)
255  return 0;
256  state = (gz_statep)file;
257 
258  /* check that we're writing and that there's no error */
259  if (state->mode != GZ_WRITE || state->err != Z_OK)
260  return 0;
261 
262  /* since an int is returned, make sure len fits in one, otherwise return
263  with an error (this avoids a flaw in the interface) */
264  if ((int)len < 0) {
265  gz_error(state, Z_DATA_ERROR, "requested length does not fit in int");
266  return 0;
267  }
268 
269  /* write len bytes from buf (the return value will fit in an int) */
270  return (int)gz_write(state, buf, len);
271 }
272 
273 /* -- see zlib.h -- */
274 z_size_t ZEXPORT gzfwrite(buf, size, nitems, file)
275  voidpc buf;
276  z_size_t size;
277  z_size_t nitems;
278  gzFile file;
279 {
280  z_size_t len;
281  gz_statep state;
282 
283  /* get internal structure */
284  if (file == NULL)
285  return 0;
286  state = (gz_statep)file;
287 
288  /* check that we're writing and that there's no error */
289  if (state->mode != GZ_WRITE || state->err != Z_OK)
290  return 0;
291 
292  /* compute bytes to read -- error on overflow */
293  len = nitems * size;
294  if (size && len / size != nitems) {
295  gz_error(state, Z_STREAM_ERROR, "request does not fit in a size_t");
296  return 0;
297  }
298 
299  /* write len bytes to buf, return the number of full items written */
300  return len ? gz_write(state, buf, len) / size : 0;
301 }
302 
303 /* -- see zlib.h -- */
304 int ZEXPORT gzputc(file, c)
305  gzFile file;
306  int c;
307 {
308  unsigned have;
309  unsigned char buf[1];
310  gz_statep state;
311  z_streamp strm;
312 
313  /* get internal structure */
314  if (file == NULL)
315  return -1;
316  state = (gz_statep)file;
317  strm = &(state->strm);
318 
319  /* check that we're writing and that there's no error */
320  if (state->mode != GZ_WRITE || state->err != Z_OK)
321  return -1;
322 
323  /* check for seek request */
324  if (state->seek) {
325  state->seek = 0;
326  if (gz_zero(state, state->skip) == -1)
327  return -1;
328  }
329 
330  /* try writing to input buffer for speed (state->size == 0 if buffer not
331  initialized) */
332  if (state->size) {
333  if (strm->avail_in == 0)
334  strm->next_in = state->in;
335  have = (unsigned)((strm->next_in + strm->avail_in) - state->in);
336  if (have < state->size) {
337  state->in[have] = (unsigned char)c;
338  strm->avail_in++;
339  state->x.pos++;
340  return c & 0xff;
341  }
342  }
343 
344  /* no room in buffer or not initialized, use gz_write() */
345  buf[0] = (unsigned char)c;
346  if (gz_write(state, buf, 1) != 1)
347  return -1;
348  return c & 0xff;
349 }
350 
351 /* -- see zlib.h -- */
352 int ZEXPORT gzputs(file, str)
353  gzFile file;
354  const char *str;
355 {
356  int ret;
357  z_size_t len;
358  gz_statep state;
359 
360  /* get internal structure */
361  if (file == NULL)
362  return -1;
363  state = (gz_statep)file;
364 
365  /* check that we're writing and that there's no error */
366  if (state->mode != GZ_WRITE || state->err != Z_OK)
367  return -1;
368 
369  /* write string */
370  len = strlen(str);
371  ret = gz_write(state, str, len);
372  return ret == 0 && len != 0 ? -1 : ret;
373 }
374 
375 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
376 #include <stdarg.h>
377 
378 /* -- see zlib.h -- */
379 int ZEXPORTVA gzvprintf(gzFile file, const char *format, va_list va)
380 {
381  int len;
382  unsigned left;
383  char *next;
384  gz_statep state;
385  z_streamp strm;
386 
387  /* get internal structure */
388  if (file == NULL)
389  return Z_STREAM_ERROR;
390  state = (gz_statep)file;
391  strm = &(state->strm);
392 
393  /* check that we're writing and that there's no error */
394  if (state->mode != GZ_WRITE || state->err != Z_OK)
395  return Z_STREAM_ERROR;
396 
397  /* make sure we have some buffer space */
398  if (state->size == 0 && gz_init(state) == -1)
399  return state->err;
400 
401  /* check for seek request */
402  if (state->seek) {
403  state->seek = 0;
404  if (gz_zero(state, state->skip) == -1)
405  return state->err;
406  }
407 
408  /* do the printf() into the input buffer, put length in len -- the input
409  buffer is double-sized just for this function, so there is guaranteed to
410  be state->size bytes available after the current contents */
411  if (strm->avail_in == 0)
412  strm->next_in = state->in;
413  next = (char *)(state->in + (strm->next_in - state->in) + strm->avail_in);
414  next[state->size - 1] = 0;
415 #ifdef NO_vsnprintf
416 # ifdef HAS_vsprintf_void
417  (void)vsprintf(next, format, va);
418  for (len = 0; len < state->size; len++)
419  if (next[len] == 0) break;
420 # else
421  len = vsprintf(next, format, va);
422 # endif
423 #else
424 # ifdef HAS_vsnprintf_void
425  (void)vsnprintf(next, state->size, format, va);
426  len = strlen(next);
427 # else
428  len = vsnprintf(next, state->size, format, va);
429 # endif
430 #endif
431 
432  /* check that printf() results fit in buffer */
433  if (len == 0 || (unsigned)len >= state->size || next[state->size - 1] != 0)
434  return 0;
435 
436  /* update buffer and position, compress first half if past that */
437  strm->avail_in += (unsigned)len;
438  state->x.pos += len;
439  if (strm->avail_in >= state->size) {
440  left = strm->avail_in - state->size;
441  strm->avail_in = state->size;
442  if (gz_comp(state, Z_NO_FLUSH) == -1)
443  return state->err;
444  memcpy(state->in, state->in + state->size, left);
445  strm->next_in = state->in;
446  strm->avail_in = left;
447  }
448  return len;
449 }
450 
451 int ZEXPORTVA gzprintf(gzFile file, const char *format, ...)
452 {
453  va_list va;
454  int ret;
455 
456  va_start(va, format);
457  ret = gzvprintf(file, format, va);
458  va_end(va);
459  return ret;
460 }
461 
462 #else /* !STDC && !Z_HAVE_STDARG_H */
463 
464 /* -- see zlib.h -- */
465 int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
466  a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
467  gzFile file;
468  const char *format;
469  int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
470  a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
471 {
472  unsigned len, left;
473  char *next;
474  gz_statep state;
475  z_streamp strm;
476 
477  /* get internal structure */
478  if (file == NULL)
479  return Z_STREAM_ERROR;
480  state = (gz_statep)file;
481  strm = &(state->strm);
482 
483  /* check that can really pass pointer in ints */
484  if (sizeof(int) != sizeof(void *))
485  return Z_STREAM_ERROR;
486 
487  /* check that we're writing and that there's no error */
488  if (state->mode != GZ_WRITE || state->err != Z_OK)
489  return Z_STREAM_ERROR;
490 
491  /* make sure we have some buffer space */
492  if (state->size == 0 && gz_init(state) == -1)
493  return state->error;
494 
495  /* check for seek request */
496  if (state->seek) {
497  state->seek = 0;
498  if (gz_zero(state, state->skip) == -1)
499  return state->error;
500  }
501 
502  /* do the printf() into the input buffer, put length in len -- the input
503  buffer is double-sized just for this function, so there is guaranteed to
504  be state->size bytes available after the current contents */
505  if (strm->avail_in == 0)
506  strm->next_in = state->in;
507  next = (char *)(strm->next_in + strm->avail_in);
508  next[state->size - 1] = 0;
509 #ifdef NO_snprintf
510 # ifdef HAS_sprintf_void
511  sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12,
512  a13, a14, a15, a16, a17, a18, a19, a20);
513  for (len = 0; len < size; len++)
514  if (next[len] == 0)
515  break;
516 # else
517  len = sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11,
518  a12, a13, a14, a15, a16, a17, a18, a19, a20);
519 # endif
520 #else
521 # ifdef HAS_snprintf_void
522  snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8, a9,
523  a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
524  len = strlen(next);
525 # else
526  len = snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8,
527  a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
528 # endif
529 #endif
530 
531  /* check that printf() results fit in buffer */
532  if (len == 0 || len >= state->size || next[state->size - 1] != 0)
533  return 0;
534 
535  /* update buffer and position, compress first half if past that */
536  strm->avail_in += len;
537  state->x.pos += len;
538  if (strm->avail_in >= state->size) {
539  left = strm->avail_in - state->size;
540  strm->avail_in = state->size;
541  if (gz_comp(state, Z_NO_FLUSH) == -1)
542  return state->err;
543  memcpy(state->in, state->in + state->size, left);
544  strm->next_in = state->in;
545  strm->avail_in = left;
546  }
547  return (int)len;
548 }
549 
550 #endif
551 
552 /* -- see zlib.h -- */
553 int ZEXPORT gzflush(file, flush)
554  gzFile file;
555  int flush;
556 {
557  gz_statep state;
558 
559  /* get internal structure */
560  if (file == NULL)
561  return Z_STREAM_ERROR;
562  state = (gz_statep)file;
563 
564  /* check that we're writing and that there's no error */
565  if (state->mode != GZ_WRITE || state->err != Z_OK)
566  return Z_STREAM_ERROR;
567 
568  /* check flush parameter */
569  if (flush < 0 || flush > Z_FINISH)
570  return Z_STREAM_ERROR;
571 
572  /* check for seek request */
573  if (state->seek) {
574  state->seek = 0;
575  if (gz_zero(state, state->skip) == -1)
576  return state->err;
577  }
578 
579  /* compress remaining data with requested flush */
580  (void)gz_comp(state, flush);
581  return state->err;
582 }
583 
584 /* -- see zlib.h -- */
585 int ZEXPORT gzsetparams(file, level, strategy)
586  gzFile file;
587  int level;
588  int strategy;
589 {
590  gz_statep state;
591  z_streamp strm;
592 
593  /* get internal structure */
594  if (file == NULL)
595  return Z_STREAM_ERROR;
596  state = (gz_statep)file;
597  strm = &(state->strm);
598 
599  /* check that we're writing and that there's no error */
600  if (state->mode != GZ_WRITE || state->err != Z_OK)
601  return Z_STREAM_ERROR;
602 
603  /* if no change is requested, then do nothing */
604  if (level == state->level && strategy == state->strategy)
605  return Z_OK;
606 
607  /* check for seek request */
608  if (state->seek) {
609  state->seek = 0;
610  if (gz_zero(state, state->skip) == -1)
611  return state->err;
612  }
613 
614  /* change compression parameters for subsequent input */
615  if (state->size) {
616  /* flush previous input with previous parameters before changing */
617  if (strm->avail_in && gz_comp(state, Z_BLOCK) == -1)
618  return state->err;
619  deflateParams(strm, level, strategy);
620  }
621  state->level = level;
622  state->strategy = strategy;
623  return Z_OK;
624 }
625 
626 /* -- see zlib.h -- */
628  gzFile file;
629 {
630  int ret = Z_OK;
631  gz_statep state;
632 
633  /* get internal structure */
634  if (file == NULL)
635  return Z_STREAM_ERROR;
636  state = (gz_statep)file;
637 
638  /* check that we're writing */
639  if (state->mode != GZ_WRITE)
640  return Z_STREAM_ERROR;
641 
642  /* check for seek request */
643  if (state->seek) {
644  state->seek = 0;
645  if (gz_zero(state, state->skip) == -1)
646  ret = state->err;
647  }
648 
649  /* flush, free memory, and close file */
650  if (gz_comp(state, Z_FINISH) == -1)
651  ret = state->err;
652  if (state->size) {
653  if (!state->direct) {
654  (void)deflateEnd(&(state->strm));
655  free(state->out);
656  }
657  free(state->in);
658  }
659  gz_error(state, Z_OK, NULL);
660  free(state->path);
661  if (close(state->fd) == -1)
662  ret = Z_ERRNO;
663  free(state);
664  return ret;
665 }
local z_size_t gz_write(gz_statep state, voidpc buf, z_size_t len)
Definition: gzwrite.c:178
#define local
Definition: zutil.h:37
#define OF(args)
Definition: zconf.h:292
#define Z_BLOCK
Definition: zlib.h:173
#define deflateInit2(strm, level, method, windowBits, memLevel, strategy)
Definition: zlib.h:1797
#define Z_NO_FLUSH
Definition: zlib.h:168
int err
Definition: gzguts.h:197
uInt avail_in
Definition: zlib.h:88
#define GT_OFF(x)
Definition: gzguts.h:217
int ZEXPORT gzsetparams(gzFile file, int level, int strategy)
Definition: gzwrite.c:585
#define Z_ERRNO
Definition: zlib.h:180
#define z_off64_t
Definition: zconf.h:513
int mode
Definition: gzguts.h:177
z_stream strm
Definition: gzguts.h:200
#define Z_STREAM_ERROR
Definition: zlib.h:181
int ZEXPORT gzwrite(gzFile file, voidpc buf, unsigned len)
Definition: gzwrite.c:246
z_off64_t pos
Definition: zlib.h:1820
#define z_const
Definition: zconf.h:237
local int gz_init(gz_statep state)
Definition: gzwrite.c:17
int ZEXPORT gzputc(gzFile file, int c)
Definition: gzwrite.c:304
z_off64_t skip
Definition: gzguts.h:194
#define DEF_MEM_LEVEL
Definition: zutil.h:66
#define Z_FINISH
Definition: zlib.h:172
z_size_t ZEXPORT gzfwrite(voidpc buf, z_size_t size, z_size_t nitems, gzFile file)
Definition: gzwrite.c:274
struct gzFile_s * gzFile
Definition: zlib.h:1300
unsigned char * in
Definition: gzguts.h:182
#define zstrerror()
Definition: gzguts.h:133
#define Z_DEFLATED
Definition: zlib.h:209
unsigned size
Definition: gzguts.h:180
#define Z_DATA_ERROR
Definition: zlib.h:182
#define GZ_WRITE
Definition: gzguts.h:161
struct gzFile_s x
Definition: gzguts.h:172
local int gz_zero(gz_statep state, z_off64_t len)
Definition: gzwrite.c:145
#define Z_STREAM_END
Definition: zlib.h:178
int ZEXPORT gzclose_w(gzFile file)
Definition: gzwrite.c:627
int ZEXPORT gzputs(gzFile file, const char *str)
Definition: gzwrite.c:352
local int gz_comp(gz_statep state, int flush)
Definition: gzwrite.c:73
#define Z_MEM_ERROR
Definition: zlib.h:183
int seek
Definition: gzguts.h:195
int ZEXPORT gzflush(gzFile file, int flush)
Definition: gzwrite.c:553
z_const Bytef * next_in
Definition: zlib.h:87
#define Z_OK
Definition: zlib.h:177
gz_state FAR * gz_statep
Definition: gzguts.h:202
#define Z_NULL
Definition: zlib.h:212
z_stream FAR * z_streamp
Definition: zlib.h:108
#define MAX_WBITS
Definition: zconf.h:270
#define ZEXPORT
Definition: zconf.h:380
#define ZEXPORTVA
Definition: zconf.h:383